Rental prices
The housing market in Hamburg is quite competitive, leading to relatively high rental prices in comparison to other German cities. Average prices in Hamburg lie between 11 and 13 euros per square metre. The so-called Kaltmiete (lit. 'cold rent') doesn’t include heating, water and electricity, while the Warmmiete is what you can expect to pay with utilities (other than internet) included.
Deposits and additional costs
In addition to your rent, you will have to pay a Kaution, a deposit usually two or three times the Kaltmiete. Finally, the words Provision, Maklergebühr or Courtage indicate that you will have to pay a (generally large) sum of money to a real estate agent. Officially speaking, these costs are supposed to be covered by the landlord, but be careful about loopholes in the system.
How to read listings
The number of Zimmer ('rooms') indicates the number of bedrooms, offices or living rooms. Bathrooms, hallways and kitchens are not counted as rooms. The first floor (1. OG, 1. Stockwerk) means the first floor above the ground. The ground floor (which in the US would often be the first floor) is called ’Erdgeschoss’ (EG) or ’Parterre’. It isn’t customary to rent fully furnished rooms or flats unless it’s for a sublease/sublet or Zwischenmiete (lit. 'between rent'). Unfurnished (unmöbliert) typically means that you won't even find kitchen appliances or lighting fixtures. Instead, you will have to buy and install everything yourself.
It's also advisable to look out for cheap utilities providers, as the system is privatised and electricity and gas can be drawn from your company of choice. The same is true for the internet and telephone connection, but unlike water, gas and electricity, you will find it inoperative upon moving in. What you will not find at all is air conditioning. It's simply 'not a thing' in Germany. Instead, most rental contracts demand you to air out your new home regularly to avoid mould.
Tenant rights
Tenants have a relatively good position in the German legal system. For example, landlords are obliged to give renters a three-month notice period before termination of leases.